OP wrote " So I did find the Stocks app in Applications. I tried to delete it - drag it to the trash can - but wouldn't delete. Tried the context menu but no delete option. "
OP wrote " That cleared it up.StocksWidget is Apple Software and "considered safe". "
That sounds about right
Whether the user ( you ) use the Builtin Application or not, it will always be located in the Applications folder
Any Application that comes installed as part of the Operating System ( Sequoia ) can not be deleted >> full stop
The Operating System resides in a Sealed and Read Only Volume that cannot be opened by the User nor by Third Party Applications.
If you feel that any Builtin In Application is unsafe or should not included in macOS Sequoia
Suggest you contact Apple Directly and request that Apple Re-write the Entire Operating System, only this time to leave out the Stock application
To aid in contacting Apple Directly
Start now and open an Apple Support Ticket as they are PAID Apple Employees to deal will these types of issues .
Product Feedback - and make it known to Apple of your request
call 1 800 MyApple
Other location Call Centres
Contact Apple for support and service